[PATCH 5.17 0304/1126] ASoC: sh: rz-ssi: Drop calling rz_ssi_pio_recv() recursively

Greg Kroah-Hartman
2022-04-05T08:08:14Z

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

[ Upstream commit 6570f991582e32b7992601d0497c61962a2c5dcc ]

Instead of recursively calling rz_ssi_pio_recv() use a while loop
to read the samples from RX fifo.

This also fixes an issue where the return value of rz_ssi_pio_recv()
was ignored when called recursively.

Fixes: 03e786bd4341 ("ASoC: sh: Add RZ/G2L SSIF-2 driver")
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20220110094711.8574-2-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/sh/rz-ssi.c | 68 ++++++++++++++++++++++---------------------
1 file changed, 35 insertions(+), 33 deletions(-)

diff --git a/sound/soc/sh/rz-ssi.c b/sound/soc/sh/rz-ssi.c
index e8d98b362f9d..2ac2c9722b3b 100644
--- a/sound/soc/sh/rz-ssi.c
+++ b/sound/soc/sh/rz-ssi.c
@@ -411,54 +411,56 @@ static int rz_ssi_pio_recv(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
{
struct snd_pcm_substream *substream = strm->substream;
struct snd_pcm_runtime *runtime;
+ bool done = false;
u16 *buf;
int fifo_samples;
int frames_left;
- int samples = 0;
+ int samples;
int i;

if (!rz_ssi_stream_is_valid(ssi, strm))
return -EINVAL;

runtime = substream->runtime;
- /* frames left in this period */
- frames_left = runtime->period_size - (strm->buffer_pos %
- runtime->period_size);
- if (frames_left == 0)
- frames_left = runtime->period_size;

- /* Samples in RX FIFO */
- fifo_samples = (rz_ssi_reg_readl(ssi, SSIFSR) >>
- SSIFSR_RDC_SHIFT) & SSIFSR_RDC_MASK;
-
- /* Only read full frames at a time */
- while (frames_left && (fifo_samples >= runtime->channels)) {
- samples += runtime->channels;
- fifo_samples -= runtime->channels;
- frames_left--;
- }
+ while (!done) {
+ /* frames left in this period */
+ frames_left = runtime->period_size -
+ (strm->buffer_pos % runtime->period_size);
+ if (!frames_left)
+ frames_left = runtime->period_size;
+
+ /* Samples in RX FIFO */
+ fifo_samples = (rz_ssi_reg_readl(ssi, SSIFSR) >>
+ SSIFSR_RDC_SHIFT) & SSIFSR_RDC_MASK;
+
+ /* Only read full frames at a time */
+ samples = 0;
+ while (frames_left && (fifo_samples >= runtime->channels)) {
+ samples += runtime->channels;
+ fifo_samples -= runtime->channels;
+ frames_left--;
+ }

- /* not enough samples yet */
- if (samples == 0)
- return 0;
+ /* not enough samples yet */
+ if (!samples)
+ break;

- /* calculate new buffer index */
- buf = (u16 *)(runtime->dma_area);
- buf += strm->buffer_pos * runtime->channels;
+ /* calculate new buffer index */
+ buf = (u16 *)(runtime->dma_area);
+ buf += strm->buffer_pos * runtime->channels;

- /* Note, only supports 16-bit samples */
- for (i = 0; i < samples; i++)
- *buf++ = (u16)(rz_ssi_reg_readl(ssi, SSIFRDR) >> 16);
+ /* Note, only supports 16-bit samples */
+ for (i = 0; i < samples; i++)
+ *buf++ = (u16)(rz_ssi_reg_readl(ssi, SSIFRDR) >> 16);

- rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
- rz_ssi_pointer_update(strm, samples / runtime->channels);
+ rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
+ rz_ssi_pointer_update(strm, samples / runtime->channels);

- /*
- * If we finished this period, but there are more samples in
- * the RX FIFO, call this function again
- */
- if (frames_left == 0 && fifo_samples >= runtime->channels)
- rz_ssi_pio_recv(ssi, strm);
+ /* check if there are no more samples in the RX FIFO */
+ if (!(!frames_left && fifo_samples >= runtime->channels))
+ done = true;
+ }

return 0;
}
--
2.34.1